This paper furnishes a comparison of the results obtained from three observations made on an atrophic infant in which the absorption of fat was determined. Each observation lasted for three days, during which time the fat in the food and feces was determined.
For twelve days immediately preceding the first observation the infant was fed exclusively on human milk and the first observation succeeded this preliminary period without interruption. There was an interval of four days between the first and second observations and an interval of three days between the second and third observations.
During the first observation the infant was given 840 c.c. of breastmilk daily. During the second observation he was given 840 c.c. daily of a mixture of cows' milk containing approximately 3 per cent. of fat, 6 per cent, of milk-sugar and 1 per cent, of protein.
During the third observation the infant was given